Self-healing diaphragm in a subcutaneous infusion port

Abstract

A subcutaneous infusion port comprising a three-piece removable unit including a self-sealing, needle penetrable diaphragm having a composite membrane comprising a bottom layer that has the properties of being inert, being impermeable to fluid and preventing tissue in-growth and a middle layer laminated to the bottom layer that has the properties of promoting tissue in-growth into the middle layer.

What is claimed: 
     
       1. A subcutaneous infusion port for peritoneal dialysis, comprising: (a) a housing forming an inner chamber and including   (i) a vertically extending side wall disposed about the chamber, the side wall having a first and a second axially spaced ends and inside and outside side walls, the side wall forming a generally cylindrical chamber;   (ii) an entry port into the chamber located at the second end of the side wall;   (iii) a bottom solid wall axially disposed at the first end of the side wall;   (iv) an attaching means disposed at the first end of the side wall for fixing the housing to a patient;   (b) a replaceable self-sealing, self-healing, needle penetrable diaphragm axially located near the second end of the sidewall for sealing the entry port and for maintaining the sealed inner chamber, the diaphragm comprising:   (i) a bottom layer constructed of a material having properties of being inert, impermeable to fluid and preventing tissue in-growth and the bottom layer facing the bottom solid wall;   (ii) a layer above the bottom layer and laminated to the bottom layer, the layer above the bottom layer constructed of a material having properties that promote tissue in-growth;   (c) a removable sealing means in contact with both the side wall and the diaphragm in order to securely hold the diaphragm to the housing and to provide a leak resistant seal between the diaphragm and housing;   (d) a conduit for attaching to a standard dialysis catheter, wherein said conduit extends out from the outside side wall and is located near the first end of the side wall, the conduit having a fluid entry port which is in alignment with the conduit and which interconnects with the inner chamber for a fluid flow passage.   
     
     
       2. A subcutaneous infusion port according to claim 1, wherein the bottom layer of the diaphragm is composed of a layer selected from the PTFE group consisting of polytetrafluoroethylene and expanded porous polytetrafluoroethylene and a uniform layer of an elastomer glue located directly above the PTFE layer. 
     
     
       3. A subcutaneous infusion port according to claim 1, wherein the layer above the bottom layer and laminated to the bottom layer of the diaphragm is selected from the group consisting of dacron, nylon, cotton, polyethylene and polypropylene. 
     
     
       4. A subcutaneous infusion port according to claim 1, wherein the attaching means includes a radially extending flange that extends around the periphery of the infusion port, the flange having one or more suture sites to fix the infusion port to a patient. 
     
     
       5. A subcutaneous infusion port according to claim 1, wherein the sealing means includes a screw ring that twists off the housing for diaphragm replacement. 
     
     
       6. A subcutaneous infusion port according to claim 1, wherein the conduit attaches to a standard dialysis catheter. 
     
     
       7. A subcutaneous infusion port according to claim 1, wherein the bottom wall is composed of a material that is virtually impenetrable by a hydrodermic needle. 
     
     
       8. A subcutaneous infusion port according to claim 1, wherein the housing is selected from the group consisting of polyethylene, polycarbonates, polyurethane, polyvinyl chloride, and metals such as stainless steel and titanium. 
     
     
       9. A subcutaneous infusion port according to claim 1, wherein the removable sealing means is designed to allow for ease of replacement of the diaphragm without having to remove the housing.